In Measuring Angst, artist Jonathan Schipper has designed a robot that holds fragile pieces of beer-bottle glass in its knuckles, pulling them apart and putting them back together again in an endless loop. But because glass is so cheap, the break isn’t so much drawn from life because if you throw a bottle against a wall, it just smashes into thousands of little pieces. “So I broke it more gently,” Schipper tells Co.Design.

The bottle pieces rotate in slow motion and take nearly 12 minutes to complete as they gradually explode into smaller fragments before rewinding and starting again. The trickiest part, Schipper says, is the joint on the knuckle that has an axis at the end of the rotation, which has involved several versions because it has to move back and forth without a lot of backlash but still hold the bottle pieces successfully.

The first design used a spring and a pulley; the second design had two cables on either side, so when it was unplugged, it would still go back to the original position. “Basically, the computer doesn’t know where it is when it wakes up,” he says. The third, and current, version of the piece uses a brake, because, as Schipper notes, “I want to move them to a safe position so when power comes off, the brakes still engage in a ‘hold’ position.”

For the programming, Schipper uses Visual Basic, a user-friendly programming language that allows him to create a few custom controls, with a set of cards that Microsoft whiz Peter Norton designed for simple motion control and commands. “But I’m not sure I’ve solved it yet,” Schipper says. “It gets shown four or five times, and each time, it gets refined a little bit more to make it work better.”